1. (a.) Cooperating; acting together to produce an effect.

2. (n.) That which unites in action with something else to produce the same effect.

3. (n.) A number or letter put before a letter or quantity, known or unknown, to show how many times the latter is to be taken; as, 6x; 8x; here 6 and 8 are coefficients of x.

4. (n.) A number, commonly used in computation as a factor, expressing the amount of some change or effect under certain fixed conditions as to temperature, length, volume, etc.; as, the coefficient of expansion; the coefficient of friction.

coacting coactive coadjutant coadjuvant collaborative collective collectivist collectivistic collusive combined commensal common communal communalist communalistic communist communistic communitarian concerted concordant concurrent concurring conjoint conniving cooperant cooperating cooperative ecumenic fellow harmonious harmonized joint mutual noncompetitive reciprocal symbiotic synergetic synergic synergistic uncompetitive